The present invention relates to a silver halide emulsion, more specifically, the present invention relates to a silver halide emulsion ensuring high sensitivity, high contrast and low fog, reduced in the fluctuation of sensitivity due to difference in the humidity condition in aging after exposure or at the exposure, and exhibiting excellent reciprocity law characteristics at high illuminance. The present invention also relates to a production method of the emulsion and a silver halide photographic light-sensitive material using the emulsion.
The silver halide emulsion for use in silver halide photographic light-sensitive materials is usually subjected to a chemical sensitization using various chemical substances so as to obtain desired sensitivity and gradation. Representative examples of known chemical sensitization methods include sulfur sensitization, selenium sensitization, tellurium sensitization, noble metal sensitization using gold or the like, reduction sensitization and various sensitization methods using a combination thereof. Recently, silver halide photographic light-sensitive materials are strongly demanded to have high sensitivity, excellent graininess, high sharpness and rapid processability with expedited progress of development and to cope with these requirements, various improvements have been made on the above-described sensitization methods.
Also, color printing papers are demanded to have enhanced sensitivity, image quality and performance at the processing, such as toughness, and to satisfy these requirements, an emulsion ensuring high sensitivity and high contrast and an emulsion reduced in the fluctuation of photographic properties due to difference in the temperature and humidity conditions at exposure are demanded. On the other hand, apparatuses for laser scanning exposure are recently widespread and therefore, suitability for short-time and high-illuminance exposure becomes one of importance performances. The laser scanning exposure is greatly characterized in that the exposure can be performed at a high speed and the resolution can be improved. However, the color printing paper to which the laser scanning exposure is applied must have suitability for unprecedentedly short-time (specifically 10xe2x88x926 sec.) and high-illuminance exposure.
Among those sensitization methods, most widely and commonly used is a gold-sulfur sensitization method using a so-called labile sulfur compound capable of reacting with silver ion to produce silver sulfide and a gold compound. This method is described in detail, for example, in P. Grafikides, Chimie et Physique Photographique, 5th ed., Paul Montel (1987), T. H. James (compiler), The Theory of the Photographic Process, 4th ed., Macmillan (1977), and H. Frieser, Die Grundlagen der Photographischen Prozesse mit Silber-halogeniden, Akademische Verlagasgeselshaft (1968).
In applying a gold-sulfur sensitization to a silver halide emulsion, a method of individually adding a labile sulfur compound capable of reacting with silver ion to produce silver sulfide and a gold compound is generally used and this method is described in the publications cited above and also in Nippon Shashin Gakkai Shi (Journal of Japan Photographic Society), vol. 50, No. 2, page 108 et seq. (1987) and Journal of the Optical Society of America, vol. 39, No. 6, page 494 et seq. (1949). The gold compound and the labile sulfur compound used in the methods described in these publications are a chloroauric acid and a thiourea compound or a thiosulfate, respectively. However, use of these compounds has various problems, for example, the attained elevation of sensitivity is not sufficiently high, fogging is readily generated, the gradation is softened and the light-sensitive material after storage for a long period of time undergoes serious generation of fog. Thus, means to solve these problems is keenly demanded.
As for the method of applying gold-sulfur sensitization using a gold compound other than the chloroauric acid, methods using a gold complex of thioethers described in JP-B-38-6447 (the term xe2x80x9cJP-Bxe2x80x9d as used herein means an xe2x80x9cexamined Japanese patent publicationxe2x80x9d) and JP-A-62-85239 (the term xe2x80x9cJP-Axe2x80x9d as used herein means an xe2x80x9cexamined published Japanese patent applicationxe2x80x9d), a gold complex of rhodanines described in JP-A-1-147537, a gold complex of mesoions described in JP-A-4-267249, or a gold complex of hydantoins described in JP-A-4-268550 are known. However, these methods all are not satisfactory for solving the above-described problems.
JP-A-4-67032, JP-A-4-75053 and JP-A-4-86649 describe gold complex compounds which, it is stated, have an effect of improving the increase of fog in aging of a light-sensitive material for a long period of time and preventing the deterioration of graininess accompanying the increase of fog. These compounds, however, all fail in exhibiting an activity enough to solve the above-described problems.
Other than these, a gelatin dispersion of gold sulfide colloid is generally known as a gold sensitizer. A preparation method of gold sulfide colloid is described in Research Disclosure, Item 37154, page 227 (March, 1995), however, if a gold sulfide colloid is prepared according to this method, as described in Nippon Shashin Gakkai Dai 15 Kai Shuki Kenkyu Happyo Kai Koen Yoshi Shu (Japan Photographic Society, 15th Autumn Meeting for Presentation of Researches, Summary of Lectures), page 26, cyan ion which is environmentally harmful is disadvantageously produced as a by-product. Furthermore, since the gold thiocyanate is sparingly soluble such that the solubility product is about 25, precipitates undesired in view of production may be disadvantageously produced.
Other than the above-described Au(I) compounds containing a monovalent gold atom, Au(III) compounds containing a trivalent gold atom, such as chloroauric acid, are also known as the gold sensitizer. The chloroauric acid is sufficiently stable in an aqueous solution but gives photographic properties insufficient in view of, for example, sensitivity, gradation, suitability for high-illuminance exposure and toughness against temperature and humidity environments at the exposure. Thus, this compound is still in need of improvements.
JP-A-4-204724 describes a method for applying gold-selenium sensitization to a silver halide emulsion, where a labile selenium compound capable of reacting with silver ion to produce silver selenide and a gold compound are separately added. This technique also incurs conspicuous increase of fog and cannot solve the above-described problems.
Under these circumstances, the present invention has been made to solve the above-described problems.
One object of the present invention is to provide a silver halide photographic light sensitive material in which a specific gold-chalcogen complex is used and thereby which is ensured with low fog and high sensitivity, reduced in the generation of fogging during storage for a long period of time, less fluctuated in the sensitivity due to aging after exposure and favored with high contrast.
Another object of the present invention is to provide a silver halide color photographic light-sensitive material which is advantageous in view of cost and environment, ensures high sensitivity and high contrast, less fluctuates in the sensitivity due to difference in the humidity condition at the exposure and exhibits excellent high-illuminance reciprocity law characteristics.
Still another object of the present invention is to provide a preparation method of gold sulfide collide, which is preferred to the environment from the standpoint of producing no cyan ion.
These objects of the present invention can be attained by the followings.
A silver halide emulsion comprising at least one monovalent Au(I) complex coordinated with a compound represented by the following formula (1):
R1xe2x80x94Chxe2x80x94R2xe2x80x83xe2x80x83(1) 
wherein R1 and R2 each independently represents an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group, R1 and R2 may combine with each other to form a 3-, 4-, 5-, 6- or 7-membered ring, and Ch represents a sulfur atom, a selenium atom or a tellurium atom.
A silver halide emulsion chemically sensitized by a monovalent Au(I) complex coordinated with a compound represented by formula (1).
A chemical sensitization method for silver halide emulsions, comprising chemically sensitizing a silver halide emulsion using a monovalent Au(I) complex coordinated with a compound represented by formula (1).
The silver halide emulsion as described in [2], wherein in the Au(I) complex, Ch of formula (1) is coordinated to the gold atom.
The silver halide emulsion as described in [2], wherein the Au(I) complex is a gold complex represented by the following formula (2):
[L1xe2x80x94Au(I)xe2x80x94(L2)m]Xnxe2x80x83xe2x80x83(2) 
wherein L1 represents a compound represented by formula (1) L2 represents a compound represented by formula (1) or a halogen atom, provided that L1 and L2 may be the same or different or may be combined, X represents a counter salt necessary for neutralizing the electric charge of the compound, m represents 0 or 1, and n represents a value of 0 to 1 and may be a decimal.
The silver halide emulsion as described in [5], wherein L1 and L2 in formula (2) are the same compound and the metal complex is a symmetric gold complex.
The silver halide emulsion as described in [5], wherein in formula (2), either L1 or L2 is substituted by at least one water-soluble group.
The silver halide emulsion as described in [5], wherein in formula (2), L1 and L2 are substituted by at least one water-soluble group.
The silver halide emulsion as described in [2], wherein in formula (1), Ch is a sulfur atom.
The silver halide emulsion as described in [2], which has a silver chloride content of 90 mol % or more.
A preparation method for gold sulfide colloids, comprising preparing a gold sulfide colloid using a Au(I) complex represented by formula (2).
The preparation method for gold sulfide colloids as described in [11], wherein the gold sulfide colloid is prepared in a protective colloid solution.
A silver halide emulsion chemically sensitized by a gold sulfide colloid prepared according to the method described in [11].
A silver halide emulsion comprising at least one gold compound represented by the following formula (3):
[AuxChyMz]Wpxe2x80x83xe2x80x83(3) 
wherein Ch represents a sulfur atom, a selenium atom or a tellurium atom, M represents an alkali metal, W represents a counter salt necessary for neutralizing the electric charge of the compound, x, y and p each represents an integer of 1 or more, and z represents an integer of 0 to 2.
A silver halide emulsion chemically sensitized by a gold compound represented by formula (3).
A chemical sensitization method for silver halide emulsion, comprising chemically sensitizing a silver halide emulsion using a gold compound using a gold compound represented by formula (3).
The silver halide emulsion as described in [15], wherein in formula (3), Ch is a sulfur atom or a selenium atom.
The silver halide emulsion as described in [15], wherein in formula (3), x+y is from 4 to 40.
The silver halide emulsion as described in [15], wherein in formula (3), Au is a monovalent ion.
The silver halide emulsion as described in [15], wherein in formula (3), the [AuxChyMz] ion has a cyclic or cage structure.
The silver halide emulsion as described in [15], wherein tabular grains having an aspect ratio of 8 or more occupy 50% or more of the projected area of all silver halide grains.
A silver halide photographic light-sensitive material comprising a support having thereon at least one silver halide emulsion layer, wherein at least one of the silver halide emulsion layers contains a silver halide emulsion chemically sensitized using at least one member selected from a Au(I) complex coordinated with a compound represented by the following formula (1) and a gold compound represented by the following formula (3):
R1xe2x80x94Chxe2x80x94R2xe2x80x83xe2x80x83(1) 
wherein R1 and R2 each independently represents an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group, R1 and R2 may combine with each other to form a 3-, 4-, 5-, 6- or 7-membered ring, and Ch represents a sulfur atom, a selenium atom or a tellurium atom;
[AuxChyMz]Wpxe2x80x83xe2x80x83(3) 
wherein Ch represents a sulfur atom, a selenium atom or a tellurium atom, M represents an alkali metal, W represents a counter salt necessary for neutralizing the electric charge of the compound, x, y and p each represents an integer of 1 or more, and z represents an integer of 0 to 2.
A silver halide photographic light-sensitive material comprising a support having thereon at least one silver halide emulsion layer, wherein at least one of the silver halide emulsion layers contains at least one member selected from a Au(I) complex coordinated with a compound represented by the following formula (1) and a gold compound represented by the following formula (3):
R1xe2x80x94Chxe2x80x94R2xe2x80x83xe2x80x83(1) 
wherein R1 and R2 each independently represents an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group, R1 and R2 may combine with each other to form a 3-, 4-, 5-, 6- or 7-membered ring, and Ch represents a sulfur atom, a selenium atom or a tellurium atom;
[AuxChyMz]Wpxe2x80x83xe2x80x83(3) 
wherein Ch represents a sulfur atom, a selenium atom or a tellurium atom, M represents an alkali metal, W represents a counter salt necessary for neutralizing the electric charge of the compound, x, y and p each represents an integer of 1 or more, and z represents an integer of 0 to 2.
The compound represented by formula (1) for use in the present invention is described in detail below.
R1xe2x80x94Chxe2x80x94R2xe2x80x83xe2x80x83(1) 
In formula (1), R1 and R2 each independently represents an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group. R1 and R2 may combine with each other to form a 3-, 4-, 5-, 6- or 7-member ring.
In formula (1), the alkyl, alkenyl or alkynyl group represented by R1 and R2 is preferably a substituted or unsubstituted and linear, branched or cyclic alkyl, alkenyl or alkynyl group having from 1 to 30 carbon atoms, more preferably a substituted or unsubstituted alkyl group having from 1 to 20 carbon atoms.
In formula (1), the aryl group represented by R1 and R2 is preferably a substituted or unsubstituted and monocyclic or condensed cyclic aryl group having from 6 to 30 carbon atoms, such as phenyl group and naphthyl group, more preferably a substituted or unsubstituted phenyl group.
In formula (1), the heterocyclic group represented by R1 and R2 is preferably a substituted or unsubstituted and saturated or unsaturated 5-, 6- or 7-membered heterocyclic ring containing at least one of a nitrogen atom, an oxygen atom and a sulfur atom. This heterocyclic ring may be monocyclic or may form a condensed ring with another aryl or heterocyclic ring. The heterocyclic group is preferably a 5- or 6-membered heterocyclic group and examples thereof include a pyrrolyl group, a pyrrolidinyl group, a pyridyl group, a piperidyl group, a piperazinyl group, an imidazolyl group, a pyrazolyl group, a pyrazinyl group, a pyrimidinyl group, a triazinyl group, a quinolyl group, an isoquinolyl group, an indolyl group, an indazolyl group, a benzimidazolyl group, a pyranyl group, a chromenyl group, a thienyl group, an oxazolyl group, a thiazolyl group, a benzoxazolyl group, a benzothiazolyl group, a morpholino group and a morpholinyl group.
The compound represented by formula (1) is preferably a compound where at least one of R1 and R2 is an alkyl group, more preferably a compound where one is alkyl group and another is an aryl group, still more preferably a compound where both are an alkyl group.
R1 and R2 each may be substituted and representative examples of the substituent include a halogen atom, an alkyl group (including a cycloalkyl group, a bicycloalkyl group and a tricycloalkyl group), an alkenyl group (including a cycloalkenyl group and a bicycloalkenyl group), an alkynyl group, an aryl group, a heterocyclic group, a cyano group, a hydroxyl group, a nitro group, a carboxyl group, an alkoxy group, an aryloxy group, a silyloxy group, a heterocyclic oxy group, an acyloxy group, a carbamoyloxy group, an alkoxycarbonyloxy group, an aryloxycarbonyloxy group, an amino group (including an anilino group), an acylamino group, an aminocarbonylamino group, an alkoxycarbonylamino group, an aryloxycarbonylamino group, a sulfamoylamino group, an alkyl- or aryl-sulfonylamino group, an alkylthio group, an arylthio group, a heterocyclic thio group, a sulfamoyl group, a sulfo group, an alkyl- or aryl-sulfinyl group, an alkyl- or aryl-sulfonyl group, an acyl group, an aryloxycarbonyl group, an alkoxycarbonyl group, a carbamoyl group, an arylazo group, a heterocyclic azo group, an imido group, a phosphino group, a phosphinyl group, a phosphinyloxy group, a phosphinylamino group and a silyl group.
More specifically, examples of the substituent include a halogen atom (e.g., chlorine, bromine, iodine), an alkyl group [a linear, branched or cyclic, substituted or unsubstituted alkyl group; the alkyl group includes an alkyl group (preferably an alkyl group having from 1 to 30 carbon atoms, e.g., methyl, ethyl, n-propyl, isopropyl, tert-butyl, n-octyl, eicosyl, 2-chloroethyl, 2-cyanoethyl, 2-ethylhexyl), a cycloalkyl group (preferably a substituted or unsubstituted cycloalkyl group having from 3 to 30 carbon atoms, e.g., cyclohexyl, cyclopentyl, 4-n-dodecylcyclohexyl), a bicycloalkyl group (preferably a substituted or unsubstituted bicycloalkyl group having from 5 to 30 carbon atoms, namely, a monovalent group resulting from removing one hydrogen atom of bicycloalkane having from 5 to 30 carbon atoms, e.g., bicyclo[1,2,2]heptan-2-yl, bicyclo[2,2,2]octan-3-yl), and a tricycloalkyl group having many ring structures; the alkyl group in the substituents described below (for example, the alkyl group in an alkylthio group) means an alkyl group having such a concept], an alkenyl group [a linear, branched or cyclic, substituted or unsubstituted alkenyl group, such as an alkenyl group (preferably a substituted or unsubstituted alkenyl group having from 2 to 30 carbon atoms, e.g., vinyl, allyl, prenyl, geranyl, oleyl), a cycloalkenyl group (preferably a substituted or unsubstituted cycloalkenyl group having from 3 to 30 carbon atoms, namely, a monovalent group resulting from removing one hydrogen atom of cycloalkane having from 3 to 30 carbon atoms, e.g., 2-cyclopenten-1-yl, 2-cyclohexen-1-yl) and a bicycloalkenyl group (a substituted or unsubstituted bicycloalkenyl group, preferably a substituted or unsubstituted bicycloalkenyl group having from 5 to 30 carbon atoms, namely, a monovalent group resulting from removing one hydrogen atom of bicycloalkane having one double bond, e.g., bicyclo[2,2,]hept-2-en-1-yl, bicyclo[2,2,2]oct-2-en-4-yl)], an alkynyl group (preferably a substituted or unsubstituted alkynyl group having from 2 to 30 carbon atoms, e.g., ethynyl, propargyl, trimethylsilylethynyl), an aryl group (preferably a substituted or unsubstituted aryl group having from 6 to 30 carbon atoms, e.g., phenyl, p-tolyl, naphthyl, m-chlorophenyl, o-hexadecanoylaminophenyl), a heterocyclic group (preferably a monovalent group resulting from removing one hydrogen atom of a substituted or unsubstituted, aromatic or non-aromatic 5- or 6-membered heterocyclic compound, more preferably an aromatic 5- or 6-membered heterocyclic group having from 3 to 30 carbon atoms, e.g., 2-furyl, 2-thienyl, 2-pyrimidinyl, 2-benzothiazolyl), a cyano group, a hydroxyl group, a nitro group, a carboxyl group, an alkoxy group (preferably a substituted or unsubstituted alkoxy group having from 1 to 30 carbon atoms, e.g., methoxy, ethoxy, isopropoxy, tert-butoxy, n-octyloxy, 2-methoxyethoxy), an aryloxy group (preferably a substituted or unsubstituted aryloxy group having from 6 to 30 carbon atoms, e.g., phenoxy, 2-methylphenoxy, 4-tert-butylphenoxy, 3-nitrophenoxy, 2-tetradecanoylaminophenoxy), a silyloxy group (preferably a silyloxy group having from 3 to 20 carbon atoms, e.g., trimethylsilyloxy, tert-butyldimethylsilyloxy), a heterocyclic oxy group (preferably a substituted or unsubstituted heterocyclic oxy group having from 2 to 30 carbon atoms, e.g., 1-phenyltetrazol-5-oxy, 2-tetrahydropyranyloxy), an acyloxy group (preferably a formyloxy group, a substituted or unsubstituted alkylcarbonyloxy group having from 2 to 30 carbon atoms and a substituted or unsubstituted arylcarbonyloxy group having from 6 to 30 carbon atoms, e.g., formyloxy, acetyloxy, pivaloyloxy, stearoyloxy, benzoyloxy, p-methoxyphenylcarbonyloxy), a carbamoyloxy group (preferably a substituted or unsubstituted carbamoyloxy group having from 1 to 30 carbon atoms, e.g., N,N-dimethylcarbamoyloxy, N,N-diethylcarbamoyloxy, morpholinocarbonyloxy, N,N-di-n-octylaminocarbonyloxy, N-n-octylcarbamoyloxy), an alkoxycarbonyloxy group (preferably a substituted or unsubstituted alkoxycarbonyloxy group having from 2 to 30 carbon atoms, e.g., methoxycarbonyloxy, ethoxycarbonyloxy, tert-butoxycarbonyloxy, n-octylcarbonyloxy), an aryloxycarbonyloxy group (preferably a substituted or unsubstituted aryloxycarbonyloxy group having from 7 to 30 carbon atoms, e.g., phenoxycarbonyloxy, p-methoxyphenoxycarbonyloxy, p-n-hexadecyloxyphenoxy-carbonyloxy), an amino group (preferably an amino group, a substituted or unsubstituted alkylamino group having from 1 to 30 carbon atoms and a substituted or unsubstituted anilino group having from 6 to 30 carbon atoms, e.g., amino, methylamino, dimethylamino, anilino, N-methylanilino, diphenylamino), an acylamino group (preferably a formylamino group, a substituted or unsubstituted alkylcarbonylamino group having from 1 to 30 carbon atoms or a substituted or unsubstituted arylcarbonylamino group having from 6 to 30 carbon atoms, e.g., formylamino, acetylamino, pivaloylamino, lauroylamino, benzoylamino, 3,4,5-tri-n-octyloxyphenylcarbonylamino), an aminocarbonylamino group (preferably a substituted or unsubstituted aminocarbonylamino group having from 1 to 30 carbon atoms, e.g., carbamoylamino, N,N-dimethylaminocarbonylamino, N,N-diethylaminocarbonylamino, morpholinocarbonylamino), an alkoxycarbonylamino group (preferably a substituted or unsubstituted alkoxycarbonylamino group having from 2 to 30 carbon atoms, e.g., methoxycarbonylamino, ethoxycarbonylamino, tert-butoxycarbonylamino, n-octadecyloxycarbonylamino, N-methylmethoxycarbonylamino), an aryloxycarbonylamino group (preferably a substituted or unsubstituted aryloxycarbonylamino group having from 7 to 30 carbon atoms, e.g., phenoxycarbonylamino, p-chlorophenoxycarbonylamino, m-n-octyloxyphenoxycarbonylamino), a sulfamoylamino group (preferably a substituted or unsubstituted sulfamoylamino group having from 0 to 30 carbon atoms, e.g., sulfamoylamino, N,N-dimethylaminosulfonylamino, N-n-octylaminosulfonylamino), an alkyl- or aryl-sulfonylamino group (preferably a substituted or unsubstituted alkylsulfonylamino group having from 1 to 30 carbon atoms or a substituted or unsubstituted arylsulfonylamino group having from 6 to 30 carbon atoms, e.g., methylsulfonylamino, butylsulfonylamino, phenylsulfonylamino, 2,3,5-trichlorophenylsulfonylamino, p-methylphenylsulfonylamino), an alkylthio group (preferably a substituted or unsubstituted alkylthio group having from 1 to 30 carbon atoms, e.g., methylthio, ethylthio, n-hexadecylthio), an arylthio group (preferably a substituted or unsubstituted arylthio group having from 6 to 30 carbon atoms, e.g., phenylthio, p-chlorophenylthio, m-methoxy-phenylthio), a heterocyclic thio group (preferably a substituted or unsubstituted heterocyclic thio group having from 2 to 30 carbon atoms, e.g., 2-benzothiazolylthio, 1-phenyltetrazol-5-ylthio), a sulfamoyl group (preferably a substituted or unsubstituted sulfamoyl group having from 0 to 30 carbon atoms, e.g., N-ethylsulfamoyl, N-(3-dodecyloxypropyl)sulfamoyl, N,N-dimethylsulfamoyl, N-acetylsulfamoyl, N-benzoylsulfamoyl, N-(Nxe2x80x2-phenylcarbamoyl)sulfamoyl), a sulfo group, an alkyl- or aryl-sulfinyl group (preferably a substituted or unsubstituted alkylsulfinyl group having from 1 to 30 carbon atoms or a substituted or unsubstituted arylsulfinyl group having from 6 to 30 carbon atoms, e.g., methylsulfinyl, ethylsulfinyl, phenylsulfinyl, p-methylphenylsulfinyl), an alkyl- or aryl-sulfonyl group (preferably a substituted or unsubstituted alkylsulfonyl group having from 1 to 30 carbon atoms or a substituted or unsubstituted arylsulfonyl group having from 6 to 30 carbon atoms, e.g., methylsulfonyl, ethylsulfonyl, phenylsulfonyl, p-methylphenylsulfonyl), an acyl group (preferably a formyl group, a substituted or unsubstituted alkylcarbonyl group having from 2 to 30 carbon atoms, or a substituted or unsubstituted arylcarbonyl group having from 7 to 30 carbon atoms, e.g., acetyl, pivaloyl, 2-chloroacetyl, stearoyl, benzoyl, p-n-octyloxyphenylcarbonyl), an aryloxycarbonyl group (preferably a substituted or unsubstituted aryloxycarbonyl group having from 7 to 30 carbon atoms, e.g., phenoxycarbonyl, o-chlorophenoxycarbonyl, m-nitrophenoxycarbonyl, p-tert-butylphenoxycarbonyl), an alkoxycarbonyl group (preferably a substituted or unsubstituted alkoxycarbonyl group having from 2 to 30 carbon atoms, e. g., methoxycarbonyl, ethoxycarbonyl, tert-butoxycarbonyl, n-octadecyloxycarbonyl), a carbamoyl group (preferably a substituted or unsubstituted carbamoyl group having from 1 to 30 carbon atoms, e.g., carbamoyl, N-methylcarbamoyl, N,N-dimethylcarbamoyl, N,N-di-n-octylcarbamoyl, N-(methylsulfonyl)carbamoyl), an aryl- or heterocyclic-azo group (preferably a substituted or unsubstituted arylazo group having from 6 to 30 carbon atoms or a substituted or unsubstituted heterocyclic azo group having from 3 to 30 carbon atoms, e.g., phenylazo, p-chlorophenylazo, 5-ethylthio-1,3,4-thiadiazol-2-ylazo), an imide group (preferably N-succinimide or N-phthalimide), a phosphino group (preferably a substituted or unsubstituted phosphino group having from 2 to 30 carbon atoms, e.g., dimethylphosphino, diphenylphosphino, methylphenoxy-phosphino), a phosphinyl group (preferably a substituted or unsubstituted phosphinyl group having from 2 to 30 carbon atoms, e.g., phosphinyl, dioctyloxyphosphinyl, diethoxy-phosphinyl), a phosphinyloxy group (preferably a substituted or unsubstituted phosphinyloxy group having from 2 to 30 carbon atoms, e.g., diphenoxyphosphinyloxy, dioctyloxyphosphinyloxy), a phosphinylamino group (preferably a substituted or unsubstituted phosphinylamino group having from 2 to 30 carbon atoms, e.g., dimethoxyphosphinylamino, dimethylaminophosphinylamino), and a silyl group (preferably a substituted or unsubstituted silyl group having from 3 to 30 carbon atoms, e.g., trimethylsilyl, tert-butyldimethylsilyl, phenyl-dimethylsilyl).
Among the above-described functional groups, those having a hydrogen atom may further be substituted by a substituent described above after removing the hydrogen atom.
Among the substituents which R1 and R2 in formula (1) each may have, preferred are a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group, a cyano group, a hydroxyl group, a carboxyl group, an alkoxy group, an aryloxy group, a heterocyclic oxy group, an acyloxy group, a carbamoyloxy group, an alkoxycarbonyloxy group, an aryloxycarbonyloxy group, an amino group, an acylamino group, an aminocarbonylamino group, an alkoxycarbonylamino group, an aryloxycarbonylamino group, an alkyl- or aryl-sulfonylamino group, an alkylthio group, an arylthio group, a heterocyclic thio group, a sulfamoyl group, a sulfo group, an alkyl- or arylsulfonyl group, an acyl group, an aryloxycarbonyl group, an alkoxycarbonyl group, a carbamoyl group, an imido group, a phosphino group, a phosphinyl group, a phosphinyloxy group, a phosphinylamino group and a silyl group, more preferred are a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group, a cyano group, a hydroxyl group, a carboxyl group, an alkoxy group, an aryloxy group, a heterocyclic oxy group, an acyloxy group, a carbamoyloxy group, an alkoxycarbonyloxy group, an aryloxycarbonyloxy group, an amino group, an acylamino group, an aminocarbonylamino group, an alkoxycarbonylamino group, an aryloxycarbonylamino group, an alkyl- or aryl-sulfonylamino group, an alkylthio group, an arylthio group, a heterocyclic thio group, a sulfamoyl group, a sulfo group, an alkyl- or aryl-sulfonyl group, an acyl group, an aryloxycarbonyl group, an alkoxycarbonyl group, a carbamoyl group, a phosphinyl group and a phosphinyloxy group.
In formula (1), R1 and R2 may combine with each other to form a 3-, 4-, 5-, 6- or 7-membered ring. In this case, the ring structure formed is a saturated or unsaturated sulfur-containing heterocyclic ring and the ring may be monocyclic or may form a condensed ring with another carbon ring or heterocyclic ring. The total number of carbons is preferably 2 to 30. Examples of the ring include a thiirane ring, a thiethane ring, a thiolane ring, a thiane ring, a dithian ring, a thiepane ring, a thiomorpholine ring, a thioxane ring, a thiazole ring, a thiophene ring, a thianthrene ring, a phenoxathiine ring, a phenothiazine ring.
In formula (1), when R1 and R2 combine with each other to form a 3-, 4-, 5-, 6- or 7-membered ring, the ring structure formed may have a substituent and examples thereof are the same as those described above for the substituent which R1 and R2 may have. The preferred range of each substituent is also the same.
In the present invention, the compound represented by formula (1) preferably has a non-cyclic structure where R1 and R2 are not combined.
In the case where R1 and R2 have a substituent, the substituent is also preferably an acidic functional group or a salt thereof. The acidic functional group as the substituent of R1 and R2 is preferably a functional group capable of forming a Brxcfx86nsted acid, more preferably a functional group having a pKa value of 7 or less in water. Preferred examples of the acidic functional group for use in the present invention include a carboxyl group, a sulfo group and a phosphorus-containing acidic functional group. Among these, a carboxyl group and a sulfo group are preferred. In the case where R1 and R2 have a salt of an acidic functional group, the salt is preferably an alkali metal salt (e.g., Na salt, K salt), an alkaline earth metal salt (e.g., Ca salt, Mg salt, Ba salt), an ammonium salt, a phosphonium salt and a sulfonium salt of the above-described acidic functional groups. Furthermore, when the salt of the acidic functional group is an ammonium salt, a phosphonium salt or a sulfonium salt, an inner salt is also preferred.
In formula (1), Ch represents a sulfur atom, a selenium atom or a tellurium atom, preferably a sulfur atom or a selenium atom, and most preferably a sulfur atom.
In the present invention, the compound represented by formula (1) is preferably a compound where Ch is a sulfur atom or a selenium atom and at least one of R1 and R2 is an alkyl group, more preferably a compound where Ch is a sulfur atom, one of R1 and R2 is an alkyl group and another is an aryl group, still more preferably a compound where Ch is a sulfur atom and R1 and R2 both are an alkyl group, and most preferably a compound where Ch is a sulfur atom, R1 and R2 both are an alkyl group and at least one of R1 and R2 is substituted by an acidic functional group or a salt thereof.
The compound represented by formula (2) is described in detail below.
In formula (2), L1 represents a compound represented by formula (1) and the preferred range thereof is the same as that of formula (1). L2 represents a compound represented by formula (1) or a halogen atom and when L2 is a compound represented by formula (1), the preferred range thereof is the same as that of formula (1). In the case where L2 is a halogen atom, specific examples thereof include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. In the present invention, L2 is preferably a chlorine atom or a bromine atom, more preferably a chlorine atom.
In formula (2), L1 and L2 may be the same or different and when n represents a value except for 0, the compound represented by formula (2) is preferably a symmetric gold complex where L1 and L2 are the same compound. When n represents 0, the compound is preferably a complex where L2 is a halogen atom.
In formula (2), L1 and L2 may combine together to form a 12- to 30-membered large cyclic compound, however, in the present invention, L1 and L2 are preferably not combined and each an independent molecule. In formula (2), L1 or L2 may have a cyclic structure by itself but in the present invention, L1 and L2 each preferably has a non-cyclic structure.
In formula (2), X represents a counter ion necessary for neutralizing the electric charge of the compound. When the counter ion represented by X is anion, specific examples thereof include a halogenium ion (e.g., Fxe2x88x92, Clxe2x88x92, Brxe2x88x92, Ixe2x88x92), tetrafluoroboronate ion (BF4xe2x88x92), hexafluoro-phosphonate ion (PF6xe2x88x92), hexafluoroantimonate ion (SbF6xe2x88x92), sulfate ion (S2O42xe2x88x92), an arylsulfonate ion (e.g., p-toluenesulfonate ion, naphthalene-2,5-disulfonate ion) and a carboxy ion (e.g., acetate ion, trifluoroacetate ion, oxalate ion, benzoate ion). In the case where the counter ion represented by X is cation, specific examples thereof include an alkali metal ion (e.g., lithium cation, sodium cation, potassium cation), an alkaline earth metal ion (e.g., magnesium ion, calcium ion), a substituted or unsubstituted ammonium ion (e.g., ammonium, triethyl-ammonium, tetramethylammonium), and a substituted or unsubstituted pyridinium ion (e.g., pyridinium, 4-phenyl-pyridinium). In the present invention, the counter salt represented by X is preferably anion, more preferably a halogenium ion, a tetrafluoroboronate ion, a hexafluoro-phosphonate ion, a hexafluoroantimonate ion, a sulfate ion or an arylsulfonate ion, still more preferably a halogenium ion, a tetrafluoroboronate ion, a hexafluorophosphonate ion or a hexafluoroantimonate ion.
In formula (2), m represents 0 or 1. In the present invention, m is preferably 1.
In formula (2), n is a number of X, which is necessary for neutralizing the electric charge of the compound, and represents a value of 0 to 1. The value may be a decimal. In the present invention, n is preferably 0 or 1, more preferably 0.
In the present invention, the compound represented by formula (2) is preferably a compound where L1 is a compound represented by formula (1), L2 is a compound represented by formula (1) or a halogen atom, m is 1, and n is 0 or 1, more preferably a compound where L1 is a compound represented by formula (1), L2 is a halogen atom, m is 1 and n is 0.
Specific examples of the compounds represented by formulae (1) and (2) are set forth below, however, the present invention is not limited thereto.
The compound represented by formula (1) for use in the present invention is easily available because many compounds are available on the market. Furthermore, the compound represented by formula (2) for use in the present invention can be easily synthesized from a compound represented by formula (1) and an easily available gold compound such as chloroauric acid, sodium tetrachloroaurate (NaAuCl4), sodium tetrabromoaurate (NaAuBr4), potassium tetrachloroaurate (KAuCl4), potassium tetrabromoaurate (KAuBr4), ammonium tetrachloroaurate (NH4AuCl4) or ammonium tetrabromoaurate (NH4AuBr4), according to various known methods. The synthesis method is optimally selected according to individual compounds and therefore, a synthesis method which can be generally used may not be specified, however, the compound can be synthesized by the method described, for example, in Gmelin, Handbook Au Suppl., Vol. B1, pp. 298-300 and pp. 308-311. The synthesis methods of the compounds for use in the present invention are described below by referring to synthesis examples of representative compounds.